1. Field of the Invention
The present invention relates to a toner bottle, a method of molding the toner bottle, a method of including the toner bottle for use in an image forming apparatus in which a developing agent and/or a toner is filled and applied to the developing portion.
2. Description of the Related Art
As shown in FIG. 1A, polyethylene terephthalate (PET) bottles used for drinking are collected by a recycling manufacturer. Subsequent to washing and grinding, the collected PET bottles are sent to a recycling PET material processing trader by which the collected PET bottles are processed to materials for molding. Typical processes of collecting and processing PET bottles are:
(1) consumers separate PET bottles from other waste materials and take the PET bottles to a collecting place set by a local government;
(2) the local government selects and stores the PET bottles which are compressed and packed in bale form;
(3) a recycling manufacturer further selects, washes, resorts and grinds the bale material to a size of about 8 mm×8 mm. Subsequent to washing and drying, flake is obtained;
(4) A recycling PET material processing trader melts the flake. Thereafter, the melted flake is subject to surface crystallization treatment to obtain pellets (i.e., small particles); and
(5) The pellets are blended with flakes flame retardants and polycarbonate, injection molded and thereafter subject to heating and stretch blow molding.
In one embodiment of the invention the process of forming pellets from flakes must be carried out before forming the PET toner bottle because of the following reasons:
The main reason of forming pellets is to obtain uniform particles. Non-uniform particles tend to clog at a hopper or a mixing and kneading screw in an injection molding device, which causes trouble for continuous production Furthermore, when pellets are formed, moisture in the materials is uniformly contained. That is, when moisture is not uniformly contained, the moisture has an adverse effect when molding pellets to a toner bottle, which leads to deterioration in the strength of the material
Published unexamined Japanese patent application no. (hereinafter referred to as JOP) 2001-54911 describes a PET material recycling device for recycling waste plastic containers, for example, PET bottles, having a coarse grinding machine which grinds material to a size at least twice as large as a typically ground size i.e., a size which can pass through a screen mesh having a diameter of from 6 to 12 mm) and an air classifier which can air-classify the coarse light fragments and the coarse heavy fragments which have been ground by the coarse grinding machine. The size of the typical ground fragment is, e.g., from 6 to 12 mm, but a method of suitably obtaining ground fragments for a toner bottle is not disclosed.
As described in JOP 2003-221498, PET bottles are not reused because hopper bridging occurs when ground flake PET is placed in a molding machine. In addition, a deterioration in the physical properties of the PET is caused by hydrolysis inducing degradation.
Even when such ground flake PET is heated and melted by an extruder to prevent bridging and to obtain pellet PET, the pelletized ground PET is amorphous having a glass transition temperature of from about 70 to 80° C. and a crystallization temperature of from about 120 to 130° C. at temperature rising. Thus, blocking easily occurs during preparatory drying before molding and solidification by crystallization in a molding device cylinder and/or barrel during plasticizing is accelerated, which easily makes the screw of molding device stop.
With regard to the process of molding recycled PET to make a toner bottle described in JOP 2002-22188 an expensive phthalic acid based plasticizer is required when only recycled materials are used because the recycled materials do not have a good stretching property. In JOP 2005-193575 recycled materials are adjusted by regulating the melting conditions; however, this is not sufficient for obtaining a good product.